InChI=1S/C20H20N2O9S/c1-29-14-7-10(6-12(23)19(14)31-32(26,27)28)18-17(20(24)25)16-13(30-18)3-2-11-15(16)9(4-5-21)8-22-11/h2-3,6-8,17-18,22-23H,4-5,21H2,1H3,(H,24,25)(H,26,27,28)